On Summertime Pruning
By Norm Schilling
One
of the most frequent questions I’m asked is when to prune. Though the
answer varies with particular species and needs, I believe that for
the most part, pruning on woody perennials is best spread throughout
the year. Rather than pruning once during winter it is often better
if this is spread out over the course of several lighter prunings. There
are a couple of reasons for this.
One
is that the act of pruning is the act of creating injuries, injuries
cause stress, and stress is better handled by living beings if given
in several small doses, rather than one large one.
The
other reason is that by pruning lightly several times a year we can
be both more immediately reactive to the way the tree or shrub is growing
and more proactive in coaxing growth into forms we desire that are better
for the plant.
Lets imagine a Desert
Willow for example, well established and growing well. A good rule of
thumb for pruning woody perennials, especially trees, is not to remove
more than 25% of the foliage in a year. Normal procedure would be to
remove all of that in one pruning in the winter. However, say that winter
pruning was reduced to just 10%. Later, in the spring, after new growth
has pushed forth, the same tree is revisited. One can then observe how
the plant is responding to the winter pruning. Selective pruning of
new water sprouts and suckers should occur by removing them entirely
or heading them back to a bud to slow them down. The other responses
of the tree can be studied and the new growth that is not "behaving"
well can be slowed down or removed. In this pruning, only 5% to 10%
of foliage is removed. The tree then responds to the work of the arborist
and energy is allocated, based in part on the pruning just done, and
growth corresponds.
Following
this, in summer or early fall, the tree is visited again and the pruner
then responds to the trees late spring growth and influences and redirects
growth again. Another 5 to 10% is removed and the total for the year
does not exceed the approximate 25%. The tree responds in its fall growth
to the pruning of the summer. This approach is much more interactive
with the growth of the tree and better results can be achieved.
A
note of caution is in order though. I think that desert-adapted species
are better candidates for summer pruning than more moderate to high
water users. The higher water users are often much more susceptible
to sunburn of foliage and trunk. When tissues that were previously shaded
by other foliage are exposed to brutal summer sunlight conditions damage
can ensue. Minimize or eliminate pruning of such plants to cooler times
and be sure not to remove large chunks of shading foliage as this may
cause sun damage to the previously shaded growth.
Remember
also, that if you do just one heavy pruning a year on trees and other
woody perennials, that pruning is usually best done during the dormant
season, winter.
One final thought on
summertime pruning. Dead wood, such as twigs, branches or spent blossom
stalks can be removed at any time and will actually allow the wound
to close more quickly. Just cut all the dead off back to, but not into,
live tissue. The line between dead and live tissue is visibly obvious.
If
you’re just aching for some pruning to do in the summertime, go for
it, but just go lightly. You can remove one or two minor branches that
are bugging you, whacking you in the forehead or obscuring a view. So,
whip out the hand pruners and saw and have at it!
Publisher's
Note: Norm Schilling is a
Certified ISA Arborist and was for years the Lead Groundskeeper at The
Desert Demonstration Gardens. Until the end of July, Norm was Horticultural
Supervisor at UNLV. You may have heard him speak or attended one of
his many classes.
Norm
has just formed the Schilling Horticulture Group. When I spoke to him
a few minutes ago he was dripping wet from the rain in some lucky customers
yard.
Every once in a while
someone comes along that I feel I can recommend without hesitation and
when Norm told me he was starting his own business all I could think
of was sending out The Insider's List to tell YOU, and to ask him to
write the above article. This is exciting news for all of us.
Please
call him if you need any advice on trees, shrubs, landscaping or if
you need a Xeric landscape maintained, something pruned, planted or
a problem diagnosed. This guy is GOOD!
You can contact Norm
on his cell phone at 296-9074. Or his office at
452-5272. Or Email: Arborguy@aol.com.